U.S. patent application number 13/722992 was filed with the patent office on 2014-06-26 for system and method for providing oscillation downhole.
This patent application is currently assigned to SCHLUMBERGER TECHNOLOGY CORPORATION. The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Edward Harrigan, K. N. Satish Kumar, Murat Ocalan, Jahir Pabon, Sashank Vasireddy, Shunfeng Zheng.
Application Number | 20140174726 13/722992 |
Document ID | / |
Family ID | 50973318 |
Filed Date | 2014-06-26 |
United States Patent
Application |
20140174726 |
Kind Code |
A1 |
Harrigan; Edward ; et
al. |
June 26, 2014 |
SYSTEM AND METHOD FOR PROVIDING OSCILLATION DOWNHOLE
Abstract
A technique employs the use of oscillations downhole to
facilitate a desired functionality of a downhole tool. According to
this technique, a tool is initially conveyed downhole and operated
to perform a function that relates to a downhole application. The
operational efficiency of the tool is improved by creating
oscillating forces which vibrate the tool to achieve a desired
result, e.g. freeing the tool from a stuck position.
Inventors: |
Harrigan; Edward; (Richmond,
TX) ; Pabon; Jahir; (Newton, MA) ; Kumar; K.
N. Satish; (Sugar Land, TX) ; Vasireddy; Sashank;
(Stafford, TX) ; Ocalan; Murat; (Boston, MA)
; Zheng; Shunfeng; (Katy, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Assignee: |
SCHLUMBERGER TECHNOLOGY
CORPORATION
Sugar Land
TX
|
Family ID: |
50973318 |
Appl. No.: |
13/722992 |
Filed: |
December 20, 2012 |
Current U.S.
Class: |
166/250.01 ;
166/177.1; 166/177.2; 166/381 |
Current CPC
Class: |
E21B 31/005 20130101;
E21B 7/24 20130101; E21B 47/00 20130101; E21B 47/12 20130101; E21B
47/07 20200501; E21B 4/06 20130101; E21B 47/06 20130101; E21B 28/00
20130101 |
Class at
Publication: |
166/250.01 ;
166/381; 166/177.1; 166/177.2 |
International
Class: |
E21B 28/00 20060101
E21B028/00 |
Claims
1. A method for providing oscillations downhole, comprising:
coupling a tool and a vibrator to a conveyance; moving the
conveyance, the tool, and the vibrator downhole into a wellbore;
and operating the vibrator to enhance movement of the tool within
the wellbore by creating oscillating forces acting on the tool.
2. The method as recited in claim 1, wherein operating comprises
creating oscillating forces to free the tool from a stuck
position.
3. The method as recited in claim 1, wherein operating comprises
creating oscillating forces to improve the operational efficiency
of the tool.
4. The method as recited in claim 1, wherein operating comprises
creating oscillating forces oriented in an axial direction with
respect to the wellbore.
5. The method as recited in claim 1, wherein operating comprises
creating oscillating forces oriented in an orthogonal direction
with respect to the wellbore.
6. The method as recited in claim 1, wherein operating comprises
creating oscillating forces which exert torsional vibrating
forces.
7. The method as recited in claim 1, wherein operating the vibrator
comprises creating the oscillating forces with a conductive coil
and a magnet.
8. The method as recited in claim 1, wherein operating the vibrator
comprises creating the oscillating forces with a plurality of
conductive coils.
9. The method as recited in claim 1, wherein operating the vibrator
comprises creating the oscillating forces with a motor rotating an
eccentric mass.
10. The method as recited in claim 1, wherein operating the
vibrator comprises creating the oscillating forces with a motor
rotating a cam mechanism.
11. The method as recited in claim 1, wherein operating the
vibrator comprises creating the oscillating forces with a
piezoelectric material.
12. The method as recited in claim 1, wherein the tool comprises
sensors for gathering measurements of the tool and/or the vibrator
and further comprising utilizing the measurements to optimize the
performance and/or operation of the tool and/or vibrator.
13. The method as recited in claim 1, further comprising varying
the frequency of the oscillating forces to optimize an effect on
the tool.
14. A system for providing oscillations downhole, comprising: a
downhole tool; a vibrator; and a conveyance coupled to the downhole
tool and the vibrator, the vibrator being positioned to create
oscillating forces which act on the downhole tool.
15. The system as recited in claim 14, wherein the vibrator is
connected to the downhole tool for operation at a downhole
location.
16. The system as recited in claim 14, wherein the vibrator is
positioned at a surface location while the downhole tool is located
downhole in a wellbore, the vibrator being oriented to direct
oscillating forces through the conveyance to act on the downhole
tool.
17. The system as recited in claim 14, wherein the vibrator
comprises an electromechanical actuator.
18. The system as recited in claim 14, wherein the vibrator
comprises a pump actuator.
19. A method for providing oscillations downhole, comprising:
conveying a tool downhole; operating the tool at a downhole
location to perform a function; improving the operational
efficiency of the tool by creating oscillating forces which vibrate
the tool; and adjusting the frequency or amplitude of the
oscillating forces to optimize the operational efficiency.
20. The method as recited in claim 19, wherein further comprising
gathering measurements from at least one sensor on the tool, and
wherein adjusting comprises adjusting the operation of the tool
and/or oscillating forces based on the measurements.
Description
BACKGROUND
[0001] In many well applications, downhole tool operation can be
susceptible to a variety of parameters which limit the tool with
respect to performance of the function for which the tool was
designed. For example, tools deployed downhole via wireline can
become stuck due to differential sticking or other causes. In tool
differential sticking, the differential pressure between the
borehole and the formation creates a normal force which effectively
causes the downhole tool to adhere to the borehole wall. The tool
becomes stuck when the maximum safe wireline cable pull is less
than the force sufficient to move the tool axially in the borehole.
However, a variety of other factors can limit the movement or
progression of a tool in a downhole application.
SUMMARY
[0002] In general, a system and methodology are provided for
inducing oscillations downhole to facilitate a function of a
downhole tool. A tool is initially conveyed downhole and operated
to perform a function that relates to a downhole application. The
operational efficiency of the tool is improved by creating
oscillations which vibrate the tool to achieve a desired result,
e.g. freeing the tool from a stuck position.
[0003] However, many modifications are possible without materially
departing from the teachings of this disclosure. Accordingly, such
modifications are intended to be included within the scope of this
disclosure as defined in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Certain embodiments of the disclosure will hereafter be
described with reference to the accompanying drawings, wherein like
reference numerals denote like elements. It should be understood,
however, that the accompanying figures illustrate the various
implementations described herein and are not meant to limit the
scope of various technologies described herein, and:
[0005] FIG. 1 is a graphical example illustrating the effects of
applying an oscillating force to facilitate movement of a downhole
tool in a longitudinal direction, according to an embodiment of the
disclosure;
[0006] FIG. 2 is a schematic illustration of a well system
incorporating a vibrator to apply oscillating forces in a downhole
environment, according to an embodiment of the disclosure;
[0007] FIG. 3 is an illustration of an example of a vibrator used
to apply oscillating forces to a downhole tool, according to an
embodiment of the disclosure;
[0008] FIG. 4 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0009] FIG. 5 is a schematic illustration of oscillating forces,
i.e. vibrations, being applied in a longitudinal, e.g. axial,
direction, according to an embodiment of the disclosure;
[0010] FIG. 6 is a schematic illustration of oscillating forces
being applied in a lateral, e.g. radial, direction, according to an
embodiment of the disclosure;
[0011] FIG. 7 is a schematic illustration of oscillations being
applied as torsional forces, according to an embodiment of the
disclosure;
[0012] FIG. 8 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0013] FIG. 9 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0014] FIG. 10 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0015] FIG. 11 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0016] FIG. 12 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0017] FIG. 13 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0018] FIG. 14 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0019] FIG. 15 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0020] FIG. 16 is an illustration of an adapter that may be
utilized with the embodiment illustrated in FIG. 15 to induce
oscillating forces, according to an embodiment of the
disclosure;
[0021] FIG. 17 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0022] FIG. 18 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0023] FIG. 19 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0024] FIG. 20 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0025] FIG. 21 is a schematic illustration of a system that may be
used to induce oscillating forces, according to an embodiment of
the disclosure;
[0026] FIG. 22 is a schematic illustration of another system that
may be used to induce oscillating forces, according to an
embodiment of the disclosure;
[0027] FIG. 23 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure;
[0028] FIG. 24 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure; and
[0029] FIG. 25 is an illustration of another example of a vibrator
used to apply oscillating forces to a downhole tool, according to
an embodiment of the disclosure.
DETAILED DESCRIPTION
[0030] In the following description, numerous details are set forth
to provide an understanding of some embodiments of the present
disclosure. However, it will be understood by those of ordinary
skill in the art that the system and/or methodology may be
practiced without these details and that numerous variations or
modifications from the described embodiments may be possible.
[0031] The present disclosure generally relates to a system and
methodology for inducing oscillating forces downhole to facilitate
a function of a downhole tool. In a given downhole application, a
tool is initially conveyed downhole and operated to perform a
function. The operational efficiency of the tool is improved by
creating oscillations which vibrate the tool to achieve a desired
result. For example, the oscillations may be used to free a stuck
tool deployed by a wireline and/or to enhance a drilling function
or other function of a downhole tool.
[0032] In wireline applications, for example, tools are deployed
downhole via wireline and such tools are prone to becoming stuck in
the wellbore. In some applications, the wireline tool may become
stuck due to differential sticking which results from differential
pressure between the wellbore and the surrounding formation, thus
creating a normal force that effectively causes the tool to adhere
to the borehole wall. Sometimes the wireline tool also may become
stuck due to key-seating, friction with a borehole restriction, or
other causes that inhibit movement of the wireline tool downhole.
The wireline cable itself also can become stuck via similar causes.
By inducing suitable oscillating forces to create a larger net peak
force, the wireline tool and wireline may be freed for continued
movement along the wellbore. The oscillating force or forces may
also induce vibration in the wireline tool and the wireline, which
may assist in freeing or unsticking the wireline tool. Further, the
induced vibration may help de-stabilize and/or fluidize a mud cake
layer formed between the wireline tool and the wellbore, which may
result from such differential sticking. The oscillating force may
be applied or induced in a continuous manner or the oscillating
force may be applied as a periodic force, wherein the force is
induced in a periodic manner.
[0033] The induced oscillations also may be employed to enhance the
efficiency of other types of applications, e.g. to enhance a
desired movement of a downhole tool. By way of example, the induced
oscillating forces may be used in cutting operations, e.g. drilling
or milling operations, to enhance a function, e.g. to enhance the
rate of penetration and/or to reduce friction with the surrounding
wellbore wall. The reduced friction can be used to increase reach
and to improve load transfer to the tool, e.g. cutting bit. The
oscillations may be induced by a vibrator used in cooperation with
wireline cable. However, some applications may utilize the vibrator
and the induced oscillating forces with other types of
conveyances.
[0034] Referring generally to FIG. 1, a graphical illustration is
provided to facilitate explanation of the utilization of
oscillations which are created to act on a downhole tool. The
oscillations/vibrations induced by a vibrator may be applied in a
variety of applications, including wireline cable applications. By
way of example, the vibration may be applied while a cable pull is
applied to a wireline cable from the surface. In the graphical
example, a pull force exerted by the wireline cable is represented
by line 30 and the oscillating forces applied by a suitable
vibrator/shaker are represented by oscillating graph line 32. As
illustrated, the oscillating forces created by the vibrator cause a
larger net peak force (when the oscillation force is in phase with
the cable pull force) than can be applied by the cable alone.
[0035] Referring to FIG. 2, a schematic example of a system 34,
e.g. a well system for use in a well 36, is illustrated. Well 36
may comprise a production well, an injection well, and/or another
type of well drilled into a subterranean formation 38. In the
example illustrated, the well system 34 comprises a downhole tool
40 which is deployed into a wellbore 42 via a conveyance 44.
Additionally, the well system 34 comprises a vibrator 46, e.g. a
shaker mechanism, positioned so that oscillations induced by the
vibrator 46 act on the downhole tool 40. By way of example, the
vibrator 46 may be mounted proximate tool 40, e.g. directly above
or below tool 40. However, some embodiments may position vibrator
46 at a surface location 48, and the vibrator 46 may be designed to
utilize a medium, e.g. fluid, to deliver force oscillations
downhole through the wellbore 42 to act against downhole tool
40.
[0036] By way of example, conveyance 44 may comprise a wireline 50,
such as a single strand wireline, e.g. slickline, or a cable
wireline, e.g. a cable wireline having insulated communication
lines (electrical and/or optical communication lines or the like)
disposed within a braided cable. The conveyance 44 may also
comprise coiled tubing or jointed pipe or the like. In the example
illustrated, the downhole tool 40 has become stuck against a
sidewall of wellbore 42 by, for example, differential sticking
caused by creation of a normal force 52. Consequently, the maximum
safe cable pull is less than the force sufficient to move the tool
axially along the wellbore 42. However, the oscillating forces
caused by vibrator 46, as represented by arrows 54, create a
sufficiently large net peak force to free the downhole tool 40 when
the induced oscillation forces acting on downhole tool 40 are in
phase with a pull force 56 applied to wireline 50. It should be
noted downhole tool 40 may comprise a variety of wellbore tools,
including cutting tools used to operate a cutting bit 58, e.g. a
drilling or milling bit. The downhole tool 40 may comprise sensors
disposed therein, such as pressure, temperature, vibration sensors
or the like for gathering measurements from the tool 40 or vibrator
46. The tool 40 may be configured to communicate measurements from
the sensors via the conveyance 44 in communication with surface
equipment or the like for analysis. The communicated measurements
may be utilized for monitoring and/or optimizing the performance
and/or the operation of the tool 40 and/or the vibrator 46, such as
by making adjustment in tool operation or vibrator operation or the
like.
[0037] The oscillations induced by vibrator 46 may be caused by a
variety of mechanisms and techniques depending on the parameters of
a given downhole application. For example, the
vibrations/oscillations may be generated by combining a coil and
magnet or by utilizing a plurality of coils. In some applications,
a motor may be used to rotate an eccentric mass or to rotate a cam
mechanism. In other applications, a piezoelectric system, such as a
stack of piezoelectric devices, may be used to induce oscillations.
Fluid pumps, such as hydraulic pumps, also may be used to induce
the oscillations. Sometimes the oscillations may be induced via
acoustic impulses created by chemical charges or other types of
charges. These and other techniques may be used alone or in
combination to provide the desired oscillations/vibrations acting
against downhole tool 40 to free or otherwise facilitate movement
of the downhole tool 40 along the wellbore 42.
[0038] The vibrator 46 also may be operated or swept through a
range of frequencies and/or amplitudes. Varying the frequency, for
example, allows the system to be tuned to reach or approach
resonance where the net force applied will be at a peak value. The
resonant frequency can vary based on several criteria, including
tool geometry and mass, borehole geometry, temperature, pressure,
borehole fluid properties such as density and viscosity, mud cake
properties such a shear strength, thickness and acoustic
properties, and the position of the tool relative to the borehole
geometry. However, the frequency of the oscillations induced by the
vibrator 46 can be continually adjusted or swept to move the
oscillations toward the resonant frequency of the system. It should
be noted that the resonant properties of the system will vary as
the downhole tool 40 becomes free, i.e. unstuck, or as the system
becomes partially free. The unstuck portion will tend to have a
higher frequency but as more of the tool 40 peels away and becomes
free the resonant frequency will be reduced. However, the ability
to adjust vibrator 46 to change this frequency enables the effects
of the induced oscillations acting on the downhole tool 40 to be
enhanced. Variations in the amplitude of the oscillations (e.g.
variations in oscillation amplitude from low amplitude to high
amplitude) also may be used to facilitate movement of the downhole
tool 40 in a desired, longitudinal direction.
[0039] In some applications, control over the induced oscillations
acting on downhole tool 40 can be better controlled by placing the
vibrator 46 near a longitudinal end, e.g. the illustrated top end,
of the downhole tool 40. In this type of embodiment, the vibrator
46 may be designed with a smaller diameter than the downhole tool
40 to help position the vibrator 46 away from the surrounding wall
of wellbore 42. This allows the vibrator 46 to vibrate freely and
with a higher Q factor than it would have if it were touching the
wellbore wall.
[0040] Referring generally to FIG. 3, an example of vibrator 46 is
illustrated. In this example, the vibrator 46 is coupled to tool 40
and/or the tool string carrying downhole tool 40 and comprises an
electromechanical system 60 which vibrates. The oscillating forces
54 are induced via a vibrating mass 62 mounted about a stator 64
and between springs 66. The vibrating mass 62 may be in the form of
a magnet which may be selectively moved along the stator 64 when
electrical power is supplied to the system. Additionally, the
stator 64 may be designed to enable wiring 68 to pass through the
stator 64. When electrical power is supplied to the system via, for
example, wiring 68, the mass 62 is induced to vibrate back and
forth within a surrounding housing 70 and against springs 66. This
motion induces the oscillating forces 54 which act against downhole
tool 40 to facilitate longitudinal movement of the downhole tool
40. By way of example, stator 64 may be constructed as a conductive
coil and vibrating mass 62 may be constructed as a magnet. In FIG.
4, a similar embodiment of vibrator 46 is illustrated but springs
66 have been removed so that vibrating mass 62 impacts directly
against housing 70 which may be directly coupled to downhole tool
40.
[0041] The vibrator 46 may have a variety of constructions,
embodiments of which are described herein, and may be oriented to
induce a variety of oscillating forces 54. As illustrated in FIG.
5, for example, the vibrator 46 may be designed to induce
oscillating forces in a longitudinal, e.g. axial, direction with
respect to the wellbore 42, as indicated by arrow 72. The
longitudinal forces 72 may be oriented generally axially along the
axis of the wireline 50. The vibrator 46 also may be designed to
induce oscillating forces 54 in an orthogonal direction with
respect to the wellbore 42, as indicated by arrow 74 in FIG. 6. The
orthogonal forces 74 may be used in combination with the cable pull
to create a force vector which simultaneously pulls away from the
wellbore wall and along the wellbore axially. In some embodiments,
the vibrator 46 may be designed to induce oscillating forces 54 in
the form of torsional forces, e.g. torsional vibrating forces about
the axis of downhole tool 40, as illustrated by arrow 76 in FIG. 7
such as by providing cooperating splines and grooves on the mass 62
and/or the stator 64 in order to cause rotation of the 62 or
similar features and thereby induce a torsional force from the
vibrator 46. Additionally, various combinations of longitudinal
forces 72, orthogonal forces 74, and/or torsional forces 76 may be
employed to improve tool movement.
[0042] Referring generally to FIG. 8, another embodiment of
vibrator 46 is illustrated. In this embodiment, vibrator 46
comprises an electromagnetic mechanism 78 having a conductive coil
80 that can be energized by applying AC power from the surface and
through the wireline 50 at various frequencies and amplitudes. The
electric coil 80 generates an oscillating magnetic field which
applies a sinusoidal force on a magnet assembly 82. In the
embodiment illustrated, the oscillating movement of magnet assembly
82 creates a vibrating mass mounted for longitudinal oscillations
against springs 84. The magnetic flux lines are in a longitudinal,
e.g. axial, direction and the vibrating mass 82 is positioned
inside a stator 86. The oscillating forces 54 applied to downhole
tool 40 are created by oscillations of the magnet assembly 82
within the conductive coil 80.
[0043] In the embodiment illustrated in FIG. 9, the vibrator 46
also comprises electromagnetic mechanism 78 except the oscillating
mass is in the form of an external magnet assembly 82 in which the
oscillating magnet is mounted on springs 84 outside of electrically
conductive coil 80. Again, coil 80 is powered to generate an
oscillating magnetic field which acts on magnet assembly 82 to
create an oscillating mass. The oscillating mass, in turn, creates
the oscillating forces that induce movement of downhole tool 40. In
this embodiment, the stator 86 is positioned within magnet assembly
82. In some applications, the vibrator 46 may be designed such that
the oscillating mass/magnet assembly 82 impacts directly against a
tool body 88 of downhole tool 40. Additionally, magnet assembly 82
and stator 86 may be arranged to create magnetic flux lines in the
transverse or orthogonal direction, as created by the embodiment
illustrated in FIG. 10.
[0044] Referring generally to FIG. 11, another embodiment of
vibrator 46 is illustrated. In this embodiment, the vibrator 46
comprises a motor 90, such as an electric or hydraulic motor,
located in a surrounding housing 92. The motor 90 is coupled to an
eccentric mass 84 by a shaft 96. Operation of the motor 90 causes
rotation of shaft 96 and eccentric mass 94. The eccentricity of the
rotating mass 94 imparts a reactive vibration that induces
oscillating forces 54 on the vibrator 46 and these oscillating
forces 54 are similarly imparted against downhole tool 40.
[0045] As illustrated in FIG. 12, the motor 90 also may be coupled
to a rotatable cam mechanism 98 via shaft 96. Cam mechanism 98
comprises a cam profile 100 connected to shaft 96, and cam profile
100 is positioned to rotate against a cooperating cam profile 102
coupled to a mass 104. Rotation of cam profile 100 against
cooperating cam profile 102 causes reciprocation of mass 104
against a spring 106. The movement of reciprocating mass 104
ultimately imparts the oscillating forces 54 against downhole tool
40.
[0046] Referring generally to FIG. 13, another embodiment of
vibrator 46 is illustrated. In this embodiment, the vibrator 46
comprises a piezoelectric mechanism 108 designed to induce the
oscillating forces 54. By way of example, the piezoelectric
mechanism 108 may comprise a piezoelectric stack 110 of
piezoelectric devices. The piezoelectric stack 100 may be mounted
in or against the tool body 88 of downhole tool 40. When electric
power is applied intermittently to piezoelectric stack 110, the
expansion and contraction of the piezoelectric devices forming
stack 110 create the oscillating forces 54 which act against
downhole tool 40.
[0047] In FIG. 14, another example of vibrator 46 is illustrated.
In this embodiment, vibrator 46 utilizes a pump 112, such as a
hydraulic pump, which may be operated to initiate the oscillating
forces 54. By selectively operating the pump 112 and/or appropriate
valving 114, the oscillating forces 54 may be induced. By way of
example, pump 112 may be operatively coupled with an accumulation
chamber 116 via a hydraulic line 118. The hydraulic line 118
extends through a slide member 120 which is slidably received
within a housing 122 containing accumulation chamber 116. The slide
member 120 is sealed with respect to accumulation chamber 116 via a
seal member 124. By alternately pumping fluid into accumulation
chamber 116 via hydraulic line 118 and out of accumulation chamber
116 via valving 114, slide member 120 is reciprocated with respect
to housing 122, thus causing the reciprocating or oscillating
forces 54.
[0048] Referring generally to FIGS. 15 and 16, another example of
vibrator 46 is illustrated. It should be noted that the various
vibrators described herein are designed for use with wireline 50.
In some applications, however, various embodiments of the vibrator
46, such as the embodiment illustrated in FIGS. 15 and 16, may be
used with other types of conveyances 44. For example, the vibrator
46 may be used in combination with coiled tubing or other
conveyances to facilitate cutting operations, such as milling or
drilling operations in wellbore 42.
[0049] In the example illustrated in FIG. 15, a motor 126 rotates a
driveshaft 128 via a gearbox 130. The driveshaft 128 is
rotationally coupled with a driveshaft extension 132 such that they
are able to rotate as unit while allowing relative axial movement.
During operation of this type of vibrator 46, the driveshaft
extension 132 is brought into contact with an adapter 134 via
corresponding surface profiles 136 between the driveshaft extension
132 and the adapter 134 (see also FIG. 16). The surface profiles
136 are designed such that rotation of driveshaft 128 and
driveshaft extension 132 causes relative rotation of profiles 136.
The surface pattern of profiles 136 causes axial displacement
between the driveshaft extension 132 and the adapter 134 while the
profiles 136 are biased toward each other by a spring 138. The
axial displacements create the oscillating forces 54 which can be
used to facilitate movement of downhole tool 40. In some
applications, downhole tool 40 may comprise cutting bit 58 and the
oscillating forces 54 may be used to facilitate the cutting action
of bit 58. The enhanced cutting may be employed to improve the rate
of penetration during, for example, wireline milling or coiled
tubing drilling operations. The longitudinal oscillatory forces
generated against bit 58 also can be used to improve and extend the
reach of the coiled tubing during coiled tubing drilling
operations.
[0050] A similar embodiment is illustrated in FIG. 17 in which the
driveshaft 128 again rotates driveshaft extension 132 while
allowing relative axial movement between driveshaft 128 and
driveshaft extension 132. Spring 138 may again be positioned
between the driveshaft 128 and driveshaft extension 132. In some
embodiments, the driveshaft extension 132 is coupled directly to
downhole tool 40 which may comprise cutting bit 58. In this
example, a shuttle 140 is placed between the drive shaft 128 and an
outer mandrel 142. The shuttle 140 is designed to slide axially
with respect to the outer mandrel 142 while being prevented from
rotating with respect to outer mandrel 142. Additionally, the
shuttle 140 is engaged with the driveshaft 128 via an indexer 144,
such as a J-slot mechanism. The indexer 144 is designed so that as
the driveshaft 128 rotates, the shuttle 140 is moved in an axially
reciprocating manner with respect to the outer mandrel 142. The
indexer 144 may be arranged so that when the shuttle 140 is in the
highest position on the illustrated embodiment, a spring member 145
biases the shuttle 140 in a downward direction to strike an impact
surface 146 of driveshaft extension 132. Once the impact is
delivered, continued rotation of the driveshaft 128 in cooperation
with the indexer 144 moves the shuttle 140 back to its upper
position to enable repetition of the impact action which induces
oscillating forces 54.
[0051] Referring generally to FIG. 18, another embodiment of
vibrator 46 is illustrated. In this embodiment, the vibrator 46 is
designed as a pressure pulse system 148. The pressure pulse system
148 may be constructed to deliver a flow of actuating fluid from a
suitable surface or downhole pumping system through a main flow
passage 150. A portion of the flow delivered through main flow
passage 150 is routed through a port 152 and into a turbine chamber
154 which causes a turbine/gearbox system 156 to rotate. The
rotation causes an output shaft 158 to drive a valve 160 in a
manner which repeatedly opens and closes a port 162 and another
port 164 which connects the turbine chamber 154 with a region
external to downhole tool 40. The opening and closing of port 162
serves as a pilot action which selectively moves a spool valve 166
against a spring 168. Fluid flow through port 162 moves the spool
valve 166 against spring 168 as fluid escapes through port 169.
When flow through port 162 is closed off, spring 168 returns the
shuttle valve 166 as fluid is released from port 170. This
reciprocating motion of spool valve 166 opens and closes the main
flow passage 150 which causes pressure pulses that are directed
along the main flow passage 150 to downhole tool 40. The pressure
pulses create the oscillating forces 54 which serve to facilitate
desired movement of downhole tool 40.
[0052] In some applications, the pressure pulse system may be
positioned at a surface location 48 and may be designed to direct
pressure pulses down through the wellbore for action against
downhole tool 40. Surface pressure pulse systems may be designed to
improve delivery of the oscillating forces 54 by modeling of the
wave propagation and/or by pulsing at an appropriate frequency and
pulse width to establish a standing wave which is effective without
being damaging. Additionally, modeling of the tubing forces and
matching of the measured surface forces and/or downhole forces may
be employed to tune the frequency and amplitude for optimum
effect.
[0053] An example of a surface pressure pulse system is illustrated
schematically in FIG. 19. In this embodiment, a pressure pulser 172
is positioned between a pump 174, which receives fluid from a
supply tank 176, and coiled tubing 178. Coiled tubing 178 extends
down into wellbore 42 from a coiled tubing pressure bulkhead 180.
By introducing the pressure pulser 172 between the pump 174 and the
coiled tubing 178, pressure pulses may be generated and propagated
through fluid in coiled tubing 178 and toward a downhole end of the
coiled tubing 178 for action against downhole tool 40.
[0054] Surface pressure pulser 172 may have a variety of
configurations. For example, the pressure pulser 172 may comprise a
motor 182 driving a rotating plate 184 via a driveshaft 186, as
illustrated in FIG. 20. The rotating plate 184 comprises a number
of openings 188 which are rotated along a matching plate 190. The
adjacent, matching plate 190 also comprises a plurality of openings
192. When plate 184 is rotated and the openings 188 are aligned
with openings 192 of plate 190, fluid delivered by pump 174 passes
through the pulser 172 without restriction. However, when the
openings 188 and 192 are out of alignment, fluid flow through the
pulser 172 is restricted and a pressure pulse is generated.
Continued rotation of plate 184 with respect to plate 190 while
pump 174 is operated causes the continued creation of pressure
pulses which may be delivered downhole through coiled tubing 178 to
establish the oscillating forces 54 which act against downhole tool
40. By way of example, motor 182 may comprise an electrical motor,
a hydraulic turbine, a PDM (positive displacement mud motor), or
another suitable type of motor. It should be noted that the
pressure pulser 172 illustrated in FIG. 20 may be positioned at a
downhole location and controlled via communication lines along the
wireline 50 or along another type of conveyance 44.
[0055] Referring generally to FIG. 21, a schematic illustration is
provided of a positive pressure pulse system which provides
pressure pulses from a surface location while incorporating a
bypass. In this example, pump 174, e.g. a triplex pump, draws fluid
from tank 176 and delivers the fluid to a pressure pulser system
194 comprising a fast acting valve 196 and a variable bypass choke
198 which are operated in cooperation to create pressure pulses
that may be delivered downhole through coiled tubing 178. The
bypass 198 provides greater control over the interruption of fluid
flow through the fast acting valve 196 by allowing some fluid to
bypass the fast acting valve 196. In this example, an optional
variable choke 200 may be located between pump 174 and fast acting
valve 196. Additionally, an optional accumulator 202 may be located
between pump 174 and fast acting valve 196.
[0056] In FIG. 22, a schematic illustration is provided of a
similar pressure pulse system which may be used to deliver pressure
pulses from a surface location. However, this embodiment differs
from the embodiment illustrated in FIG. 21 because the pressure
pulse system 194 (with fast acting valve 196 and variable bypass
choke 198) is positioned to selectively vent the pump pressure from
a pump output line 204 in fluid communication with coiled tubing
178. When the fast acting valve 196 is opened, fluid is vented to
tank 176 and the pump pressure is reduced, thus creating a pressure
pulse delivered down through coiled tubing 178 to downhole tool 40.
The variable bypass choke 198 may again be operated to adjust the
pressure pulse magnitude.
[0057] Referring generally to FIG. 23, a pressure pulse device 206
is illustrated and is designed to operate on variable pressure
source fluid delivered from an upstream location, such as a surface
location. Depending on the specific application, the pressure pulse
device 206 may be located at a surface location or at a suitable
downhole location to receive variable pressure source fluid from,
for example, pressure pulse system 194. The variable pressure
source fluid is delivered to pressure pulse device 206 via an
appropriate conduit 208, such as a well tubing. By way of example,
pressure pulse device 206 may comprise a movable member 210, such
as a piston or bellows, movably mounted within a surrounding
housing 212. The variable pressure source fluid delivered through
conduit 208 causes pulsing of the movable member 210 which, in
turn, amplifies or otherwise induces a desired pulsing
characteristic to the fluid passing through conduit 208, member
210, and housing 212 and flowing into coiled tubing 178. In an
embodiment, the fluid in the conduit 208 and in that portion of the
housing 212 adjacent the conduit 208 is separate from the fluid in
the coiled tubing 178 and in that portion of the housing 212
adjacent the coiled tubing 178. The pulsing fluid directed through
coiled tubing 178 serves to provide the oscillating forces which
can be directed to act against downhole tool 40, e.g. cutting bit
58. The movable member 210 may be spring biased in a given
direction to return the movable member 210 and to enhance the
pulsing effect.
[0058] In FIG. 24, a similar embodiment of pressure pulse device
206 is illustrated. However, movable member 210 has been replaced
with an intensifier piston 214 which is slidably received in
conduit 208. The intensifier piston 214 also comprises an expanded
portion 216 which is slidably and sealably mounted within housing
212. As with the embodiment utilizing movable member 210, variable
pressure source fluid is delivered through conduit 208. The
variable pressure source fluid causes pulsing of the intensifier
piston 214 which, in turn, amplifies or otherwise induces a desired
pulsing characteristic to the fluid passing through conduit 208 and
housing 212 and flowing into coiled tubing 178. In an embodiment
and similar to that described in FIG. 23, the fluid in the conduit
208 and in that portion of the housing 212 adjacent the conduit 208
is separate from the fluid in the coiled tubing 178 and in that
portion of the housing 212 adjacent the coiled tubing 178. The
pulsing fluid directed through coiled tubing 178 serves to provide
the oscillating forces which can be directed downhole to tool 40.
The piston 214 may be spring biased in a given direction to return
the piston 214 and to enhance the pulsing effect.
[0059] In FIG. 25, another embodiment of pressure pulse device 206
is illustrated. In this embodiment, the intensifier piston 214 is
acted on by a mechanical device 218 instead of variable pressure
source fluid supplied through conduit 208. By way of example, the
mechanical device 218 may comprise a cam 220 operated by a motor or
other suitable motive unit. For example, cam 220 may be driven by a
hydraulic or electric motor coupled to the cam directly or through
a slider-crank mechanism. As illustrated, the cam 220 is positioned
against piston 214 in a manner which causes piston 214 to
oscillate. In an embodiment and similar to that described in FIGS.
23 and 24, the fluid in the conduit 208 and in that portion of the
housing 212 adjacent the conduit 208 is separate from the fluid in
the coiled tubing 178 and in that portion of the housing 212
adjacent the coiled tubing 178. In some applications, the piston
214 may be spring biased against cam 220 to facilitate the
oscillating movement. The cam 220 causes pulsing of the intensifier
piston 214 which, in turn, amplifies or otherwise induces a desired
pulsing characteristic to the fluid passing into coiled tubing 178
from a suitable fluid supply conduit, e.g. conduit 208. The pulsing
fluid directed through coiled tubing 178 serves to provide the
oscillating forces which act against downhole tool 40.
[0060] As described herein, the devices and systems used to create
the oscillating forces 54 may have a variety of configurations and
may be designed to deliver a variety of oscillating forces. For
example, the propagation of forces to the downhole tool 40 may be
through direct impact or through reaction with other components or
systems. The direction of the oscillating forces may be
longitudinal, orthogonal, torsional, or various combinations of
these forces. The vibrator mechanisms used to provide the
oscillating forces may be hydraulic, mechanical, electromechanical,
e.g. electromagnetic, other types of mechanisms, or various
combinations of these mechanisms. With electromagnetic mechanisms,
the magnetic flux direction may be transverse, longitudinal, or
oriented in another suitable direction. The various mechanical
and/or electromechanical arrangements may comprise motors combined
with cams, eccentric masses, hydraulic systems, piezoelectric
systems, and other suitable systems. Electromechanical systems
utilizing stators may be designed with inner stators or outer
stators to induce appropriate oscillations and resulting
oscillating forces. The vibrator mechanisms also may be selectively
controlled to deliver the oscillating forces with varying
frequencies and/or varying amplitudes by controlling the electrical
power, the mechanical power, and/or the hydraulic power supplied to
the mechanisms.
[0061] Depending on the parameters of a given application, the
various pulsing devices and systems described herein may be
combined with wireline and many of those systems may be deployed
downhole with the downhole tool 40. In some applications, the
inducement of oscillating forces may be accomplished by surface
devices which deliver hydraulic pulses or other types of
oscillating forces downhole to a desired location. Although many of
the embodiments described herein are very useful with wireline
deployed tools, at least some of the embodiments may be used with
coiled tubing or other conveyances. Additionally, the systems and
methodology for creating the oscillating forces may be used with a
variety of downhole tools to facilitate and enhance movement of the
tool at a downhole location.
[0062] Although a few embodiments of the disclosure have been
described in detail above, those of ordinary skill in the art will
readily appreciate that many modifications are possible without
materially departing from the teachings of this disclosure.
Accordingly, such modifications are intended to be included within
the scope of this disclosure as defined in the claims.
* * * * *